Tradition says that a 16th century mechanical monk, now owned by the Smithsonian Institution, was created by Juanelo Turriano for Spanish Emperor Charles V. The monk walks, prays, and kisses a wooden cross. (photo and video)

On PRI's radio program The World, host Lisa Mullins interviews Roman history professor Michael Carter, of Brock University in Ontario, about the life and death of Roman gladiator Diodorus, who died in the 3rd century CE.